This invention relates to electronic countermeasure systems, and in particular to techniques and apparatus for automatically changing the system's false target pattern.
The primary purpose of an electronic countermeasures system is to transmit a program of false targets in order to confuse and saturate enemy search and track radar systems. False target jamming programs are used by ECM systems to present an enemy radar operator with numerous targets on his radar display. The targets are produced by the ECM system to resemble the characteristics of an actual radar return from an aircraft, but are positioned at different ranges and angles from the actual radar return of the aircraft carrying the ECM equipment. The false targets are intended to confuse the operator and deny him information as to the position of the aircraft penetrating his air space. Ideally the enemy radar operator would be unable to distinguish between false targets and the countermeasures system carrying aircraft that is transmitting them. If, however, the operator detects a peculiarity in the pattern of targets that distinguishes the true target in its relationship to the false ones tracking of the true target can be accomplished without regard to the effect of the countermeasures system. It is therefore desirable to change the false target pattern upon the initiation of each run. Such a technique has the effect of periodically destroying the enemy radar's frame of reference thus requiring a new search for all targets in order to again detect any previously noted peculiarity. In the past, changes in false target patterns have been accomplished mechanically by changing the programming events. There is currently a need, therefore, for electronic false target pattern changing equipment that responds automatically to discrete enemy search radar events.